Utilization of Abnormal Chemstrip Result to Reflex to Microscopic Examination: A Review of 50 Consecutive Case Results From Two Hospital Sites

• Published in: American journal of clinical pathology 2018-09, Vol.150 (suppl_1), p.S120-S121
• Main Authors: Annan, Anand, Demkowicz, Ryan, Nakashima, Megan
• Format: Article
• Language: English
• Subjects: Esterase; Hemoglobin; Microscopy; Urinalysis
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1093/ajcp/aqy100.289

Abstract Objectives Urinalysis (UA) is a commonly ordered test, often with added microscopic examination (MIC). Even on automated platforms, MIC requires time-consuming interpretation by a trained technologist. We wanted to see if any clinically significant microscopic findings would be missed if MIC was added as a reflex only when the chemstrip is abnormal. Methods Results of 56 consecutive UA + MIC cases at site A and 50 consecutive UA + MIC cases from site B were compared. Site A used a CLINITEK Novus using Novus 10 cassettes of strips (Siemens, Munich, Bavaria, DE). Site B performed UA on an iRICELL using iChem VELOCITY strips (Beckman Coulter, Brea, CA, USA). Two separate cutoffs for chemstrip positivity (with “trace” result being considered either negative or positive) for leukocyte esterase, nitrate, hemoglobin, and protein were analyzed in comparison to microscopy results to calculate sensitivity of chemstrip result for each site, and results were compared between the two sites. Results At site A, 35 samples had positive microscopy. When considering chemstrip results of “trace” and above positive, the positive chemstrip was 100% sensitive for MIC abnormalities. If “trace” was considered negative, four samples had negative chemstrip and positive microscopy, giving a sensitivity of 89% (31/35). Thirty-eight samples had abnormal microscopic results at site B. If chemstrip results of “trace” and above were considered positive, 15 samples were negative by chemstrip, giving a sensitivity of 61%. If “trace” was considered negative, sensitivity dropped off to 45% (17/38). Conclusion At site A, a chemstrip with any abnormality was 100% sensitive for abnormal microscopic findings. This dropped to 89% when “trace” results were considered negative. Sensitivity was much lower at site B. A strategy using abnormal chemstrips to reflex MIC would not miss significant microscopic findings and overall reduce the time required to perform unnecessary MIC at site A.